Modelling of long term pasture production and estimation of carrying capacity of Ankole pastoral production system in South Western Uganda

摘要

TheAnkolepastoralproductionsysteminSouthWesternUgandaisbasedongrazingwithoutsupplementaryfeeding.nbsp;AstochasticsimulationmodelwasdevelopedtodeterminethedynamicsofpasturesgrazedbyAnkolecattleandtheirHolsteinFriesiancrossesandthecarryingcapacity(CC)ofthelivestockgrazingsystem.Themodelusedtheconceptofrainuseefficiencywhichrelatespastureproductiontorainfall.Acrosssectionalstudywascarriedouton16selectedfarmsanddataonnumberofanimals,sex,agegroupandsizeofavailablegrazinglandwascollected.nbsp;Thesimilaritybetweentheresultsofthesimulationrainfallrunsandfielddataareconsideredtobesatisfactory.Theoverallannualforageproductionis3905±72kg/ha.ThelowestCC(5.65±0.75)occursinlongdryseason(JunetoAugust)whilethehighestCC(1.41±0.06ha/TLU)occursinshortrainseason(SeptembertoNovember).Annualcarryingcapacityrangesbetween1.88and2.08ha/TLUwithanoverallmeanof1.95±0.04ha/TLU.Sixtythree(63%)nbsp;percentofthesurveyedfarmshavestockingratesthatarehigherthantheCCthroughouttheyearwhiletherestareoverstockedinthedryseasonsoftheyear.nbsp;TheresultsindicatethatCCisdynamicanditsvariabilityismorepronouncedwithintheyearthanbetweenyears.InresponsetoseasonalCC,themajorpointofinterventioninregardtoreductionofactualstockingratescouldbedoneinMayshortlybeforethestartofthelongdryseason.ForAnkolepastoralsystemtobesustainable,thestockingrateshouldnotgobelow1.41ha/TLU.